Contend for the Faith
Jude introduces himself as a servant of Christ and urges the faithful, too, to contend earnestly for the faith once for all delivered to them. Those who have tasted grace and then fallen away, he says, find it hard to be brought back to repentance, and he cautions the church against people who have slipped in unnoticed, turning grace into a pretext for immorality and leading others to deny Christ.
When Christians stumble, it is not because Satan is strong but because they have yielded to temptation themselves, and that is why turning back does not come easily. God sends rain on everyone alike, yet the heart that receives that grace may become good soil and bear fruit, or it may become a field overrun with thorns and thistles through greed and lust. The words of false teachers are like springs without water: plausible at first, they only deepen the thirst and in reality satisfy nothing.
The faithful must fight for their salvation even to the point of shedding blood, and the opponent in that fight may be their own idle self, or it may be Satan. Satan does not withdraw after a single defeat but presses into every unguarded moment, so the more a heart has repented, the more watchful it must remain in the Word. Since the God who rules over Satan is our Father, abiding in Christ and overcoming sin through upright living is what it looks like for God’s people to wait for the Lord’s return.